code: def test_fit(dataset_ncf_files_sorted, model_type):
      train_path, test_path, _ = dataset_ncf_files_sorted
      data = Dataset(
          train_file=train_path,
          test_file=test_path,
          n_neg=N_NEG,
          n_neg_test=N_NEG_TEST,
      )
      model = NCF(
          n_users=data.n_users,
          n_items=data.n_items,
          model_type=model_type,
          n_epochs=1,
      )
      model.fit(data)
  
file_path: recommenders/tests/unit/recommenders/models/test_ncf_singlenode.py
imports: import os
  import shutil
  import pytest
  import numpy
  import pandas
label_desc: Use image node_id 4 for calling a global function with example usage: test_fit(dataset_ncf_files_sorted, model_type) without return types